Brown sulfur dye.



' not.

UNITED STATE? PATENT OFFICE.

HEINRICH SEIDEL, OF VIENNA, AUSTRIA-HUN GARY, ASSIGNOR TO KALLE ANDCOMPANY, OF BIEBRIOH-ON-THE-RHINE, GERMANY.

BROWN SULFUR DYE.

SPECIFICATION forming part of Letters Patent No. 687,581, dated November26, 1901.

Application filed March 6, 1900.

To all whom it may concern:

Be it known that I, HEINRICH SEIDEL, a sub ject of the Emperor ofAustria-Hungary, residing at Vienna, Austria-Hungary, have inventedcertain new and useful Improvements in the Manufacture of aNew CottonDye Containing Sulfur, of which the following is a specification.

The manufacture of cellulose is nowadays almost generally carried out insuch a manner that wood-pulp is treated in closed vessels under pressurewith calcium or magnesium bisulfite. By this treatment the cellulosefiber is not attacked in any way, while the incrusting substance of thewood enters into chemical combination with the bisulfite and is therebydissolved and extracted from the cellulose. The so-obtained waste lyesof the manufacture of sulfite cellulose are a burden for this branch ofthe industry. No sufficient use having been found for it, it has mostlyserved to poison the rivers. I have how found that from these waste lyesby nontralizing and concentrating them to a certain degree and by fusingthem together with sodium sulfid and sulfur a very useful coloringmatteris obtained, which dyes brown shades of excellent fastness onunmordanted cotton from a bath made up with salt and sodium sulfid.Still more favorable results are obtained if the waste lye is freed fromlime by a treatment with sodium carbonate before it is concentrated andintroduced into the melting process. The formation of the new dye-.stuff takes place at temperatures between 150 and 280 centigrade and isfinished as soon as the melted mass becomes dry and friable. If theprocess is carried out at a temperature above 200, it is advisable toexclude the air during the last part of the operation and during thecooling of the prod- In this manner a black amorphous mass is obtainedwhich is perfectlysoluble in water. The aqueous solution can be useddirectly for dyeing cotton.

In the following I give an example for the production of the newcoloring-matter; but I do not bind myself to the relative quantities andthe temperatures mentioned.

Thirty kilos of crystallized sodium sulfid are melted in an iron panunder addition of a small quantity of water. Twenty kilos of a sulfitewaste lye from which the calcium has been previously precipitated andwhich Serial No. 7,655. (Specimens) has been concentrated up to adensity of 28 Baum are then mixed with the melted sulfid. Seven kilos offinely-ground sulfur are now added and the temperature raised, whilestirring well, to 120 to 130 centigrade until the mass begins to turntough. It is then introduced into a drying or baking stove, heat ed to atemperature of about 180 centigrade, and kept there until it is quitedry and fri' able. The so-obtained product represents after being grounda black powder, easily soluble in water, witha deep-brown color,insoluble in alcohol and solublein concentrated sulfuric acid with browncolor. The solution in concentrated sulfuric acid yields on addition ofwater a darkbrown precipitate. The aqueous solution is not changed bycans tic-soda lye. An addition of hydrochloric acid produces adark-brown precipitate.

The new coloring-matter dyes a deep brown on unmordanted cotton'from ahath made up with sodium sulfid and Glauber salt or com mon salt. Thefastness of the dyeing's is in-' creased by a subsequent treatment withchromium, copper, or iron salts.

Now what I- claim is- The new dyestuff containing sulfur, which isobtained by fusing waste lye resulting from the manufacture of sulfitecellulose after concentration together with alkaline sulfids and sulfur,and keeping the so-obtained mass at an elevated temperature until it isquite dry and friable; which represents after being ground a blackpowder easily soluble in water, or concentrated sulfuric acid with browncolor, insoluble in alcohol, the solution of which in concentratedsulfuric acid yields a dark-brown precipitate on addition of water, theaqueous solution of which is not changed by caustic-soda lye and it isprecipitated by hydrochloric acid, and which dyes a deep brown onunmordanted cotton from a bath made up with Glauber or common salt andsodium sulfid, producing shades the fastness of which is increased by asubsequent treatment with chromium, copper or iron salts.

In testimony-whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

HEINRICH SEIDEL.

